1939LANE Map 231, Names of the large croaking frog. . . Several of the fieldworkers asked their informants, ‘What does the bullfrog . . say?’ The responses to this question, consisting of imitations of the frog’s croak . . , are given in the commentary. . . 1 inf, cwCT, [tʃʌgərʌmz], nickname for frogs, from the sound of their cry; 6 infs, cCT, sw, ceMA, The bullfrog says [ˌdʒʌgəˈrʌm]; 1 inf, ceMA, The bullfrog says [tʃʌgəˈrʌəm].

1941Nature Mag. 34.139, The “song” of the bullfrog . . has been worded in a variety of ways, the most familiar of which is “jug-o’-rum.”

1944HowardWalkin’ Preacher 218 Ozarks, He has learned his music from the orchestration of the many familiar sounds of nature: the calls of birds, . . the “chugarum” of frogs, the chirping of crickets.

1963PADS 39.13 MA, For the bullfrog, jug-o-rum and jig-a-rum appear to be innovations in Easthampton and Worcester.